scripts/ci: clean-up the 20.04/22.04 confusion in ansible

scripts/ci: clean-up the 20.04/22.04 confusion in ansible

We have a bunch of references to 20.04 (which s390x is still on)
although we are basically building on 22.04 now. Clean up the textual
references and use lcitool to generate the full package list to be
consistent.

We can drop "Install packages to build QEMU on Ubuntu on non-s390x" as
when we upgrade the s390x builder to 22.04 it won't need this
workaround.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230503091244.1450613-19-alex.bennee@linaro.org>